Automatic safety blow-off cock and valve



May 11 1926. 1,584,625

D.l MCKAY AUTOMATIC SAFETY BLOW-OFF COCK AND VALVE Filed July l5 1925 igatented May l1, 1926,

UNT

TENT @FFECR DONALD MCKAY, OF MONTGOMERY, ALABAMA.

AUTOMATIC SAFETY BLOW-OFF COCK AND VALVE.

Application filed lJuly 15, 1925. Serial No. 43,874.

This invention relates to automatic safety blow ott coclrs and valves for steam boilers. The object of the invention is to provide a device of this character so constructed as to automatically cut ott the steam in case the blow off valve should' be broken or rendered inoperative in any way thereby preventing` scalding of persons in the vicinity as well as the wasting` 01"' steam.

Another object oi the invention is to provide asimple and cheap device of this character which may be readily applied to an ordinary blow off cock or to any other valve through which steam passes.

Y With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement or" parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope ot what is claimed without departing 'tromthe spirit of the invention.

ln the accompanying drawings Figure 1 represents a longitudinal section of a blow oft' cock with this improved safety valve attached shown in operative position; and

Figure 2 is a transverse section taken on the line 2-2 of Figure 1.

This automatic safety valve may be used at any desired place on a boiler` or it may be connected with any container having compressed fluid adapted to be drawn ott through a cock. y

In Figure 1 the, inner sheet or wall of a steam boiler is shown at 1 and the outer sheet or wall at 2, the steam chamber being within the sheet 1. Threaded in sheet 1 is a ball-stop in the form of a hollow nipple 5 through which the steam from chamber 3 is designed to pass into a pipe or tube 6 loated between shells 1 and 2 and with one ot which the nipple 5 has threaded engagement. The other end ot the pipe 6 is externally threaded and has threaded engagenient with a pipe 7 being inserted in said pipe and said pipe having threaded engagement with the boiler sheet 2. This pipe 7 is designed to be connect-ed with the blow ott1 valve -l() which has a threaded neck 11 engaged with the outer end of pipe 7. Said pipe 7 having an angular head 8 to facilitate its insertion and removal by means of a suitable tool.

The blow oit valve 10 is shown provided with the usual rotary valve 12 having a bore 13 extending` transversely therethrough and which when the valve is turned to the direction shown in'Figure 1 registers with the bores 1stand 15 formed in the valve casingv An operating bar or lever 16 is connected with the valve 12 and is designed to be operated from a suitable point Jfor actuating the valve to turn on or cut off the steam.

A reciprocatory plunger or piston 17 made in the form of a tube is mounted in the pipe 6 and the bore 15 of the valve casing 10. This plunger is made shorter than the combined length of these pipes and is designed to move longitudinally therein. A ball valve 18 is mounted in the pipe 6 between the adjacent end of the plunger 17 and the nipple 5. This valve 1S normally assumes the position shown in Figure 1 bearing against the end of the plunger 17 in which position it is held by the steam passing through the pipe in the direction of the arrow shown at a; The pipe 6 is shouldered near the outer end as shown at 19 to provide a seat for the ball.

It is obvious that the pipe 17 is sufficiently small to permit the steam to pass around it and out through the bore 13 of the valve 10 when said valve is open.

The plunger 17 holds the ball valve 18 normally open and prevents its being seated on the seat 19 which would occur if this pipe or plunger 17 were not provided.

In case the connection 7 should be broken otll outside the boiler, as frequently happens, the valve 12 would be moved out of the path of pipe 17 and the pressure of steam against the ball 18 would project said pipe and permit the ball to move into pipe 6 and securely seat thereby automatically cutting oft any further passage of steam.

It is to be understood that this improved blow oit cock and safety valve may be located at any suitable point in the boiler where steam is designed to be drawn oit.

I claim 1. The combination with the inner and outer walls of a luid-pressure-container, ot a pipe mounted in the out-er wall, a ball-stop mounted in the inner wall, a tube mounted at one end within the pipe, one end of the ball-stop being received within the opposite end of the tube, the tube having an internal ball-receiving shoulder, a valve casing connected to the pipe externally of the outer wall, n ballin Jthe tube, between the stop and ithe shoulder, and a. loose plunger` disposed between the vulve und the bull.

2. The. combination set up in claini l, and further characterized by the fact that the plunger is of lubularforni, thereby to permit fluid to pass through the plunger and lessen the force with which ythe plunger is expelled, when the 'ah'e easing` is broken l0 ofi", the tubular form of the plunger enabling it to centralize the ball with respect to the axis of the tube and to permit fluid to pass about the ball, when the device is in normal Working condition and When the vulve is opened.

In testimony that I cluiln the foregoing :is my own, l have hereto aflxed my signulure.

DONALD MQKY. 

